1. Field of the Invention
The present invention relates to a fuel injection apparatus and, more specific, to a fuel injection apparatus including a fuel injector that injects and supplies a fuel into a combustion chamber of an internal combustion engine such as a gasoline engine.
2. Description of the Related Art
As disclosed in, for example, the Japanese Patent Publication (unexamined) No. 351095/1999, an internal combustion engine includes a plurality of cylinder heads, and in which fuel injectors are mounted in the state of being secured respectively to each of the cylinder heads by a stopper, and a fuel is supplied from one fuel delivery pipe via a branch part of the delivery pipe to each fuel injector. FIG. 14 is an exploded perspective view for explaining a connection state between the mentioned members. In the drawing, reference numeral 1 designates a fuel delivery pipe, and numeral 11 (portion enclosed by one-dot chain line) designates a branch part of the fuel delivery pipe 1. Numeral 2 designates a fuel injector. Numeral 3 designates a stopper, numeral 4 designates an internal combustion engine, and numeral 41 designates a cylinder head of the internal combustion engine 4. In addition, all of the arrows in FIG. 14 show respectively a moving direction for incorporating each member at the time of assembling a fuel injection apparatus, which is the same as in FIG. 1 onward described later.
The stopper 3 includes a bolt insertion hole 31 and a gripper 32 for gripping the fuel injector 2. A bolt 412 is inserted through the bolt insertion hole 31 and screwed into a tapped hole 411 that is provided in the cylinder head 41, whereby the stopper 3 is secured to the cylinder head 41. The fuel injector 2 is gripped at a body thereof by the gripper 32 of the stopper 3, which is secured to each cylinder head 41, as well as a tip portion of this injector 2 is mounted onto a fuel injector mounting hole 413, thereby being secured to the cylinder head 41. Furthermore, the fuel delivery pipe 1 is connected to the other end of each fuel injector 2 at the branch part 11 thereof. Thus, fuel is supplied to each fuel injector 2 through the branch part 11 from the fuel delivery pipe 1, and injected into the combustion chamber of the internal combustion engine 4 from the injection port that is provided at the tip end of each fuel injector 2.
Meanwhile, in assembly operation at a factory of the fuel injection apparatus, hitherto the fuel delivery pipe 1, the fuel injector 2 and the stopper 3 have been supplied to the mentioned factory in the state of individual parts separate from one another. Then these individual parts are incorporated into the semi-manufactured internal combustion engine in the factory. In this case, it is required that a necessary axial adjustment or positioning between the parts is successfully achieved. However, there exist various problems as follows. One of these problems exists in that it comes to be difficult to insert and mount the stopper 3 in and on a predetermined position from outside due to restrictions in space for assembling, because of a recent trend of demanding downsizing or much higher-performance of an internal combustion engine. Another problem exists in that an electrical connector (not shown) can be connected to the fuel injector 2 only from a specific direction in the case where a fuel spray configuration of the fuel injector 2 is not axially symmetrical owing to requirements in combustion performance of the internal combustion engine 4, or due to restrictions in configuration of the periphery of the internal combustion engine 4. A further problem exists in that it is necessary to secure, at a specific angle, the fuel injector 2 with respect to the internal combustion engine 4 and the fuel delivery pipe 1. Thus, it comes to be difficult to implement an individual assembly method in situ in the conventional manner.